~fib = {[x]
    x < 2 ? x : fib[x - 1] + fib[x - 2] 
}

printf["fib[10] = %a\n", fib[10]]

@sum: {[xs] @a = 0
    @n: xs.length
    FOR [@i: 0][< n][+ 3] (
        a += xs[i]
    )
    a
}

(@l: #[1,5,-2,7]
    printf["sum[%a] = %a\n", l, sum[l]])